1. Field of the Invention
The present invention relates to voice decoding. More particularly, the present invention relates to a method and apparatus of suppressing a voice noise in a voice decoder.
2. Description of the Related Art
A vocoder including both a voice coder and a voice decoder is configured to transmit data including parameters generated by analyzing characteristics of a voice signal and to synthesize speech based on parameters of received data.
Data transmitted over a communication network, particularly a wireless communication network that transmits and receives signals on radio channels or an Internet Protocol (IP) network, may be received with transmission errors due to a radio propagation environment. Therefore, a vocoder used for mobile communication generally has a speech synthesizing function that makes a transmission/reception error environment unperceivable to a user.
In a poor wireless environment, the probability of generating a false alarm may be increased during decoding at a channel decoder. When a bad frame is mistakenly generated for a good frame or vice versa due to a channel decoding error, the false alarm may be generated. Particularly when a bad frame is mistakenly generated for a good frame, the vocoder may synthesize speech using the data of the bad frame or perform an unnecessary error correction operation on a good frame. Accordingly, if a channel decoder does not have sufficiently good decoding performance, a bad frame may cause a tonal noise.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention.